Crystal chemistry and significance of cation ordering in Mg-Al rich spinels from high-grade hornfels (Predazzo-Monzoni, NE Italy)

Mineralogical Magazine - Tập 63 Số 2 - Trang 257-262 - 1999
Francesco Princivalle1, A. Della Giusta2, Ângelo De Min3, E. M. Piccirillo3
1Universita di Trieste, Dipartimento di Scienze della Terra, Trieste, Italy
2Universita' di Padova.
3Università di Trieste.

Tóm tắt

AbstractTwo Mg-Al spinels (FAS1 and FAS2) in high-grade hornfels from the Toal de Mason skarn (Predazzo Monzoni, NE Italy) were investigated by means of single crystal X-ray diffraction and electron microprobe analysis in order to evaluate the last intra-crystalline closure temperature.The evidence provided by crystal chemical data from the investigated spinels, compared with that for two other spinels from a websterite dyke and a chlorite schist (TS2 and SP78a, respectively) with similar chemical characteristics, yielded a new empirical geothermometer. This allowed estimation of intra-crystalline temperatures as low as c. 400°C and indicates that the closure temperature of FAS1 and FAS2 is c. 500°C i.e. 150–200°C lower than the spinel crystallisation temperature.

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Tài liệu tham khảo

O’Neill, 1984, Cation distributions and thermodynamic properties of binary spinel solid solutions, Amer. Mineral., 69, 733

10.1180/minmag.1996.060.399.10

Oberti, 1982, A crystal-chemical study on six fassaites from the Predazzo-Monzoni Area, Rendiconti SIMP, 38, 649

Minguzzi, 1977, Mineralogy and geochemistry of the contact minerals in the Predazzo-Monzoni area — Part. II: The Predazzo fassaite and revision of the fassaite crystal-chemistry, Mineral. Petrog. Acta, 21, 189

Grimes, 1983, New symmetry and structure for spinel, Proc. R. Soc. Lond., 386, 333

Borsi, 1968, Isotopic age measurament of the M.Monzoni intrusive complex, Mineral. Petrog. Acta, 14, 171

Laurenzi, 1994, High resolution Ar/Ar chronology of Predazzo magmatic complex (Southem Alps, Italy), U.S. Geological Survey, circular, 1107, 8

Sheldrick, 1993, SHELX-93. Program for crystal structure refinement.

10.1007/BF00307535

10.1007/BF01163063

O’Neill, 1983, Simple spinels: crystallographic parameters, cation radii, lattice energies and cation distributions, Amer. Mineral., 68, 181

Nell, 1991, High-temperature electrical measurements and thermodynamic properties of Fe3O4-FeCr2O4-MgCr2O4-FeAl2O4 spinels, Amer. Mineral., 76, 405

10.1007/978-3-662-22283-6

10.1180/minmag.1996.060.401.06

10.1007/BF01164322

10.1007/BF00208136

Bocchi, 1987, Mineralogia e geochimica delle aree di contatto Preddazzo-Monzoni: la vesuviana, Mineral Petrog. Acta, 30, 153

10.1107/S0567739468000707

10.1127/ejm/9/4/0705

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Mineralogical Magazine

Tập 63 Số 2

257-262

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